The present invention relates to congestion control in a network. More particularly, the present invention relates to using congestion control signaling to control a packet data flow from one device to another device in a network.
Wireless communication systems and networks are used in connection with many applications, including, for example, satellite communications systems, portable digital assistants (PDAs), laptop computers, and mobile nodes (e.g., cellular telephones). One significant benefit that users of such applications obtain is the ability to connect to a network (e.g., the Internet) as long as the user is within range of such a wireless communication system.
Current wireless communication systems use either, or a combination of, circuit switching and packet switching in order to provide mobile data services to a mobile subscriber. Generally speaking, with circuit-based approaches, wireless data is carried by a dedicated (and uninterrupted) connection between the sender and recipient of data using a physical switching path. Once the direct connection is set-up, it is maintained for as long as the sender and receiver have data to exchange. The establishment of such a direct and dedicated switching path results in a fixed share of network resources being tied up until the connection is closed. When the physical connection between the sender and the receiver is no longer desired, it is torn-down and the network resources are allocated to other users as necessary.
Packet-based approaches, on the other hand, do not permanently assign transmission resources to a given call, and do not require the set-up and tear-down of physical connections between a sender and receiver of data. In general, a data flow in packet-based approaches is “packetized,” where the data is divided into separate segments of information, and each segment receives “header” information that may provide, for example, source information, destination information, information regarding the number of bits in the packet, priority information, and security information. The packets are then routed to a destination independently based on the header information. The data flow may include a number of packets or a single packet.
In a wireless communication system, the system typically includes a wired portion and a wireless portion, with the wireless portion being between the mobile node and an antenna. The antenna usually connects to devices that convert data sent on the wires to radio signals, other devices that route data to the various antennas, and/or devices that provide data content to the mobile nodes such as web pages, email, music, or video. Sometimes these packet flows can create congestion between network devices when a number of packet data streams are being sent to a network device. This can create a problem, especially if more data is sent to a network device than it is capable of handling, which can lead to a network device failure.